Molten salt electrolytes are considered safer than traditional organic electrolytes, especially for automobile applications. However, corrosion of the electron collector severely affects the performance of batteries having a molten salt electrolyte, degrading cycling ability and high rate performance. Corrosion results from the oxidation of the molten salt electrolyte on the surface of the metal collector, typically aluminum (Al) or iron (Fe), during charge or discharge. The corrosion can significantly reduce the lifetime of the battery.
Hence, if corrosion of the electron collector can be reduced, the use of safer lithium ion (Li-ion) batteries becomes practical, for example, for automobile applications.
U.S. Pat. No. 5,518,839 to Olsen describes nickel-coated aluminum electron collectors in solid-state electrochemical cells. However, this does not describe protection of electron collectors in a Li-ion battery with molten salt electrolyte.
Patents referenced in this specification are incorporated herein by reference.